League of Legends (abbreviated LoL or just League) is a multiplayer online battle arena video game developed and published by Riot Games for Microsoft Windows and OS X. The game follows a freemium model and is supported by microtransactions, and was inspired by the Warcraft III: The Frozen Throne mod, Defense of the Ancients. In League of Legends, players assume the role of an unseen "summoner" that controls a "champion" with unique abilities and battle against a team of other players or computer-controlled champions. The goal is usually to destroy the opposing team's "nexus", a structure which lies at the heart of a base protected by defensive structures. Each League of Legends match is discrete, with all champions starting off fairly weak but increasing in strength by accumulating items and experience over the course of the game. League of Legends was generally well received at release, and has grown in popularity. By July 2012, League of Legends was the most played PC game in North America and Europe in terms of the number of hours played. As of January 2014, over 67 million people played League of Legends per month, 27 million per day, and over 7.5 million concurrently during peak hours. League of Legends has an active and widespread competitive scene. In North America and Europe, Riot Games organizes the League Championship Series, located in Los Angeles and Berlin respectively, which consists of 10[5] professional teams in each continent. Similar regional competitions exist in China, South Korea, Taiwan, South America, and Southeast Asia. These regional competitions culminate with the annual World Championship, which in 2013, had a grand prize of $1 million and attracted 32 million viewers online. The 2014 and 2015 tournaments each gave out one of the largest prize pools in eSports history, at 2.3 million dollars. Winners also receive trophies, such as the Summoner's Cup, which was made by silversmiths Thomas Lyte.